Fluid temperature adjusting device

ABSTRACT

A fluid temperature adjusting device includes: a heater configured to heat a fluid passing through a fluid passageway; a peltier module including a plurality of peltier elements, the peltier module being configured to heat or cool the fluid passing through the fluid passageway; and a controller configured to divide a total thermal energy for keeping the fluid at a target temperature into a thermal energy to be supplied from the heater and a thermal energy to be supplied from the peltier module to give the total thermal energy from both the heater and the peltier module to the fluid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2011-278981, filed Dec. 20, 2011, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a fluid temperature adjusting device.

2. Description of the Related Art

The semiconductor manufacture and the like have a process of cleaning a semiconductor such as a semiconductor wafer using a heated liquid. In the process of cleaning the semiconductor, the semiconductor is cleaned by a liquid of which the temperature is adjusted to a predetermined temperature in response to each process. The temperature of the liquid is different for each process, and may be a temperature (for example, 15° C.) lower than a room temperature or a temperature (for example, 50° C.) higher than a room temperature. Since the adjustment in the temperature of the liquid is handled by the same temperature control device, there is a demand that a temperature adjusting device needs to be equipped with both heating and cooling functions. As a device for satisfying such a demand, a peltier module is widely used.

Since the cleaning liquid is degraded when the cleaning liquid is used for a long period of time, the cleaning liquid is replaced when the cleaning liquid is degraded to some extent. When replacing the cleaning liquid, there is a need to increase the temperature of the liquid at a room temperature to, for example, 50° C., but it takes a time until the temperature of the liquid increases to some extent. Recently, there is an increasing demand for the improvement in the wafer processing speed per unit time, and hence the temperature increasing time needs to be shortened. Here, since the process of cooling the chemical liquid (the cleaning liquid) occupies a small time compared to the process of heating the liquid to a high temperature, the shortening of the cooling time is not strongly demanded. Therefore, a temperature control device has been developed which shortens a temperature increasing time by adding a heater to a temperature control device equipped with a peltier module. For example, Japanese Laid-open Patent Publication No. 2007-87774 discloses a method of controlling a liquid temperature adjusting device that uses a peltier module with a plurality of peltier elements and a heater.

In Japanese Laid-open Patent Publication No. 2007-87774, the amount of the power supplied to the peltier module is decreased or the supply of the power is stopped while using the heater together simultaneously when starting a new liquid injecting process. Thus, in a normal state, the liquid is kept at a target temperature by controlling the temperature of the liquid through the control of the supply of the power to the peltier module.

In the technique disclosed in Japanese Laid-open Patent Publication No. 2007-87774, the amount of the power supplied to the peltier module is decreased or the supply of the power is stopped simultaneously when starting the new liquid injecting process, but only the peltier module is used in the control of keeping the liquid at the target temperature. For this reason, in the technique disclosed in Japanese Laid-open Patent Publication No., although the heater is provided, its usage is limited. Accordingly, in the control for keeping the fluid at the target temperature, the capability of the heater is not used. As a result, the fluid may not be promptly adjusted to the target temperature.

When the fluid is heated by both the peltier module and the heater, the maximum heating capability may be increased, so that the temperature increasing time (the time until the liquid becomes the target temperature) may be shortened. Here, when the fluid is simultaneously heated by both the peltier module and the heater, the inside of the device is overheated, and hence there is a possibility that the durability may be degraded. When there is a possibility that the overheating may occur, the operation amount (the supplied thermal energy) is limited. In this way, it is possible to shorten a temperature increasing time while suppressing degradation in the durability. In general, the heater uses a cycle control or a duty control through an AC power supply, but has a limitation in the output resolution of the thermal energy. In a region where the thermal energy output resolution of the heater influences the temperature control result, the temperature control performance is improved by mainly using the heating of the peltier module, and hence the temperature increasing time may be shortened.

SUMMARY OF THE INVENTION

It is an object of the present invention to at least partially solve the problems in the conventional technology. A fluid temperature adjusting device comprises: a heater configured to heat a fluid passing through a fluid passageway; a peltier module including a plurality of peltier elements, the peltier module being configured to heat or cool the fluid passing through the fluid passageway; and a controller configured to divide a total thermal energy for keeping the fluid at a target temperature into a thermal energy to be supplied from the heater and a thermal energy to be supplied from the peltier module to give the total thermal energy from both the heater and the peltier module to the fluid.

The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating an example of a semiconductor wafer processing device that includes a fluid temperature adjusting device according to the embodiment;

FIG. 2 is a diagram of a cooling and heating device that is included in the fluid temperature adjusting device according to the embodiment;

FIG. 3 is a control block diagram of a controller that is included in the fluid temperature adjusting device according to the embodiment;

FIG. 4 is a diagram illustrating a change in the upper limit value of an operation amount;

FIG. 5 is a diagram illustrating a change in the upper limit value of the operation amount; and

FIG. 6 is a diagram illustrating an example of an operation amount of a peltier module and an operation amount of a heater.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A mode for carrying out the invention (hereinafter, referred to as an embodiment) will be described in detail by referring to the drawings. The invention is not limited to the content to be described in the embodiment below. Further, configurations described below include a configuration which may be easily supposed by the person skilled in the art, a substantially same configuration, and an equivalent configuration. Furthermore, the configurations described below may be appropriately combined with each other. Further, the configurations may be omitted, replaced, or modified without departing from the spirit of the invention.

FIG. 1 is a schematic diagram illustrating an example of a semiconductor wafer processing device that includes a fluid temperature adjusting device according to the embodiment. FIG. 2 is a diagram of a cooling and heating device that is included in the fluid temperature adjusting device according to the embodiment. A semiconductor wafer processing device 100 illustrated in FIG. 1 is a device that cleans a semiconductor wafer W of silicon or the like using a fluid L such as heated pure water in a manufacturing process of a semiconductor device. The semiconductor wafer processing device 100 includes a fluid temperature adjusting device 1, a control device 2, a liquid tank 3, fluid pipes 4A to 4G, a pump 5, valves 6A to 6C, and a cleaning unit 7.

The fluid temperature adjusting device 1 is a device that heats or cools a fluid L for cleaning the semiconductor wafer W so as to adjust the temperature thereof. In the embodiment, the fluid L is a liquid such as pure water, but the fluid L is not limited to the liquid and may be a gas. Regardless of the type of the fluid L, the fluid may be other than pure water.

Liquid temperature adjusting device A fluid temperature control device 10 includes a controller 11, a heater driving unit 12, and a peltier driving unit 13. The controller 11 is, for example, a microcomputer, and includes a calculation device of a CPU (Central Processing Unit) and a storage device such as a memory. The heater driving unit 12 and the peltier driving unit 13 are, for example, driver circuits that include a switching element.

The controller 11 controls an operation of at least one of the heater driving unit 12 and the peltier driving unit 13 based on, for example, the operation amount which is input from the control device 2 or the operator's manual operation. Further, since the controller 11 protects a cooling and heating device 20, the controller performs a control in which an upper limit value is set in the operation amount. The controller 11 realizes such a control in a manner such that the calculation device executes a command of a computer program stored in the storage device.

At least one of the heater driving unit 12 and the peltier driving unit 13 drives at least one of a heater 22 and a peltier module 23 included in the cooling and heating device 20 based on the instruction value transmitted from the controller 11. The above-described operation amount is an index which corresponds to the amount of the thermal energy that is exchanged between the cooling and heating device 20 and the fluid L. The operation amount is obtained, for example, based on the target temperature of the fluid L by the control device 2.

In the embodiment, the controller 11 divides the total thermal energy for keeping the fluid L at the target temperature by heating the fluid L into the supply amount of the heater 22 and the supply amount of the peltier module 23, and gives the thermal energies from both the heater 22 and the peltier module 23 to the fluid L. The supply amount of the heater 22 is a ratio of a heating output of the heater 22 with respect to the maximum heating capability of the heater 22, and the supply amount of the peltier module 23 is a ratio of a heating output of the peltier module 23 with respect to the maximum heating capability of the peltier module 23. The supply amount corresponds to a so-called operation amount. With such a configuration, it is possible to shorten a time until the fluid L becomes the target temperature in the fluid temperature adjusting device 1 which includes the peltier module 23 and the heater 22. Further, when cooling the fluid L, the controller 11 drives only the peltier module 23 so as to remove the thermal energy from the fluid L and hence cools the fluid L. Furthermore, not only in a case where the fluid L is kept at the target temperature, but also, for example, in a case where the temperature of the new fluid L is increased by heating the fluid L when the new fluid is supplied thereto, the controller 11 may divide the thermal energy into the supply amount of the heater 22 and the supply amount of the peltier module 23 and give the thermal energies from both the heater 22 and the peltier module 23 to the fluid L.

As illustrated in FIGS. 1 and 2, the cooling and heating device 20 includes a heater 22 which heats the fluid L passing through a fluid passageway 21 and a peltier module 23 which is a module of a peltier element for heating or cooling the fluid L passing through the fluid passageway 21. The peltier module 23 includes a plurality of peltier elements. The fluid passageway 21 is formed inside a body 20B. The body 20B is formed of a material which does not easily generate impurities when contacting the fluid L and is not easily affected by acid or alkali. As such a material, for example, fluorine resin is known. In the embodiment, the body 20B is formed of fluorine resin. Since the fluid passageway 21 is formed inside the body 20B, the fluid L which passes through the fluid passageway 21 contacts the fluorine resin. Since the fluorine resin does not easily generate impurities as described above, the fluorine resin is particularly suitable for the case where the cooling and heating device 20 is applied to the semiconductor manufacturing process in which impurities need to be removed as much as possible.

The heater 22 is attached to the inside of a heat transfer member (a heat transfer plate) 24 provided in the fluid passageway 21. The peltier module 23 is attached on the surface of the heat transfer member 24, and is disposed at a position away from the fluid passageway 21 in relation to the heat transfer member 24. That is, the cooling and heating device 20 is provided with the heater 22 and the peltier module 23 which are disposed in an order from the fluid passageway 21.

The fluid L which flows from a fluid inlet 211 of the fluid passageway 21 is heated by the heater 22 and the peltier module 23 while passing through the fluid passageway 21 so as to increase in temperature. Further, the fluid L which passes through the fluid passageway 21 is cooled by the peltier module 23. The peltier module 23 is used both to cool and heat the fluid L. The heater 22 is used only to heat the fluid L.

The fluid L of which the temperature is adjusted by at least one of the heater 22 and the peltier module 23 flows out of a fluid outlet 21E. An outlet temperature sensor 31 which measures the temperature of the fluid L of which the temperature has been adjusted is provided at the downstream side (at the downstream side in the circulation direction of the fluid L) of the fluid outlet 21E. Further, the heat transfer member 24 is provided with a heat transfer member temperature sensor 32 which measures the temperature of the heat transfer member 24.

In the embodiment, as illustrated in FIG. 2, the outside of the peltier module 23 is provided with a heat absorbing and radiating device 25 which cools the peltier module 23. The heat absorbing and radiating device 25 promotes an operation of absorbing and radiating the heat of the peltier module 23. As illustrated in FIG. 2, two heat transfer members 24, two peltier modules 23, and two heat absorbing and radiating devices 25 are disposed at each of both sides of the fluid passageway 21. That is, the cooling and heating device 20 includes four heat transfer members 24, four peltier modules 23, and four heat absorbing and radiating devices 25. In the embodiment, one heat transfer member 24 includes three heaters 22.

Next, the fluid passageway 21 will be described in detail. As illustrated in FIG. 2, the fluid passageway 21 includes a branched passageway 21M, a plurality of heat exchange portions 21EX, and a collecting passageway 21C. The branched passageway 21M which is introduced from the outside of the body 20B thereinto is branched inside the body 20B, and the branched portions are respectively connected to the plurality of (in the embodiment, four) heat exchange portions 21EX. Further, the respective heat exchange portions 21EX are connected to the collecting passageway 21C inside the body 20B. The respective heat exchange portions 21EX are arranged so as to face the heat transfer member 24. In each heat exchange portion 21EX, for example, a liquid contact member which has high corrosion resistance and generates a small amount of impurities is disposed in the heat transfer member 24. The collecting passageway 21C is integrated with the inside of the body 20B, and is drawn to the outside of the body 20B. The above-described outlet temperature sensor 31 may be provided at the downstream side in the circulation direction of the fluid L in relation to the heat exchange portion 21EX and may be provided at the collecting passageway 21C.

The fluid L which flows from the fluid inlet 211 of the fluid passageway 21 into the branched passageway 21M is introduced from the branched passageways 21M to the respective heat exchange portions 21EX. The fluid L inside the heat exchange portion 21EX performs a heat exchange operation with respect to the heat transfer member 24. The fluid L of which the temperature increases or decreases in the heat exchange portion 21EX flows into the collecting passageway 21C, and flows to the outside of the body 20B from the fluid outlet 21E of the fluid passageway 21. In this way, the cooling and heating device 20 heats or cools the fluid L.

In the embodiment, it is desirable that the heating capabilities (the rated heating outputs) of the heater 22 and the peltier module 23 be not extremely different from each other and it is more desirable that the heating capabilities be equal to each other. In the embodiment, the controller 11 gives the total energy supplied to the fluid L while the energy is divided into the supply amount of the heater 22 and the supply amount of the peltier module 23 when heating the fluid L so as to keep the fluid L at the target temperature. Since the heating capabilities of the heater 22 and the peltier module 23 are not extremely different from each other, it is possible to easily perform a control in which the total energy supplied to the fluid L is divided. Further, it is possible to effectively use the heating capabilities of the heater 22 and the peltier module 23 without any waste.

The semiconductor wafer processing device 100 illustrated in FIG. 1 is a device which is called a sheet cleaning device that includes a plurality of cleaning units 7 for cleaning the semiconductor wafer W one by one. In the semiconductor wafer processing device 100, the fluid temperature adjusting device 1 increases the temperature of the fluid L when cleaning the semiconductor wafer W. For this reason, the fluid temperature adjusting device 1 needs to have a function of promptly increasing the temperature of the fluid L to the necessary temperature. Since the fluid temperature adjusting device 1 may heat the fluid L by using both the peltier module 23 and the heater 22, it is possible to promptly increase the temperature of the fluid L. As a result, in the semiconductor wafer processing device 100 which increases the temperature of the fluid L by the fluid temperature adjusting device 1, it is possible to shorten the time from the cleaning start time of the semiconductor wafer W to the cleaning end time thereof.

The fluid temperature adjusting device 1 heats the fluid L by using both the peltier module 23 and the heater 22, but the heater 22 may be provided in a compact size at a comparatively low cost. For this reason, the size of the cooling and heating device 20 may be decreased, and the manufacture cost may be decreased. Further, since the fluid temperature adjusting device 1 exhibits the same heating capability in both the peltier module 23 and the heater 22, there is no need to increase one-side heating capability. For this reason, it is possible to suppress an increase in cost caused when increasing any heating performance of the peltier module 23 or the heater 22. Further, since the peltier module 23 may control the heating amount or the cooling amount with high precision, it is possible to suppress degradation in the stability of the temperature of the fluid L in a region where the heating amount is particularly small.

Control Device

The control device 2 is a device which controls the entire operation of the semiconductor wafer processing device 100. The control device 2 is, for example, a microcomputer, and includes a calculation device of a CPU (Central Processing Unit) and a storage device such as a memory. The control device 2 obtains the operation amount of the cooling and heating device 20 in a manner such that the calculation device executes a command or a computer program stored in, for example, the storage device, and transmits the operation amount to the controller 11 of the fluid temperature adjusting device 1. The operation amount is defined based on, for example, a difference between the temperature (the target temperature) of the fluid L suitable for cleaning the semiconductor wafer W and the temperature of the fluid L after adjusting the temperature thereof by the cooling and heating device 20. In a case where the control device 2 obtains the operation amount, for example, the control device 2 obtains a difference between the target temperature of the fluid L and the temperature of the fluid L obtained from the outlet temperature sensor 31 provided at the downstream side of the fluid outlet 21E of the cooling and heating device 20, and obtains the operation amount so that the difference becomes 0.

In addition, the control device 2 controls the operations of the pump 5 and the valves 6A to 6C included in the semiconductor wafer processing device 100. Further, the control device 2 controls the temperature of the fluid L inside the liquid tank 3 based on the temperature of the fluid L accumulated in the liquid tank 3 and obtained from a liquid tank temperature sensor 33 provided in the liquid tank 3.

Liquid Tank, Pipe, Pump, Valve, and Cleaning Unit

The liquid tank 3 is a device which accumulates the fluid L for cleaning the semiconductor wafer. The liquid tank 3 and the fluid inlet 21I of the cooling and heating device 20 are connected to each other by the pipe 4A. The pipe 4A sends the fluid L inside the liquid tank 3 to the cooling and heating device 20. The pipe 4B is connected to the fluid outlet 21E of the cooling and heating device 20. The pump 5 is provided in the course of the pipe 4B. The pipe 4B at the discharge port side of the pump 5 is connected to the pipe 4C. As for the pipe 4C, one side thereof is connected to the liquid tank 3, and the other side thereof is branched to the plurality of pipes 4D. Each pipe 4D is provided with the valve 6.

The semiconductor wafer W to be cleaned is cleaned at the outlet side of each pipe 4D. The portion is the cleaning unit 7. The fluid L having been used for cleaning the semiconductor wafer W is collected in the pipe 4F through the pipe 4E. One end side of the pipe 4F is connected to the liquid tank 3. The valve 6B is provided at the side of the liquid tank 3 of the pipe 4F in relation to the cleaning unit 7 closest to the liquid tank 3. Further, the other end side of the pipe 4F is connected to the pipe 4G. The pipe 4G is provided with the valve 6C.

When the semiconductor wafer W is not cleaned, the control device 2 drives the pump 5 in a state where all valves 6A are closed and the fluid L is not supplied to each of the cleaning units 7. At this time, the control device 2 controls the fluid temperature adjusting device 1 so that the temperature of the fluid L accumulated in the liquid tank 3 becomes a predetermined temperature. With such a configuration, the fluid L circulates between the fluid temperature adjusting device 1 and the liquid tank 3, so that the temperature of the fluid L inside the liquid tank 3 is adjusted to a predetermined temperature.

When the semiconductor wafer W is cleaned, the control device 2 drives the pump 5 and opens the valve 6A of the cleaning unit 7 for cleaning the semiconductor wafer W. At this time, the control device 2 controls the fluid temperature adjusting device 1 so that the temperature of the fluid L becomes a temperature suitable for cleaning the semiconductor wafer W. With such a configuration, the fluid L of which the temperature is adjusted to a temperature suitable for cleaning the semiconductor wafer W is supplied from the fluid temperature adjusting device 1 to the semiconductor wafer W to be cleaned.

When the fluid L having been used for the cleaning operation may be used, the fluid L is returned to the liquid tank 3 after it is filtrated through the pipe 4F and the valve 6B. When the amount of impurities contained in the fluid L having been used for the cleaning operation increases, the control device 2 closes the valve 6B and opens the valve 6C so that the fluid L is discharged to the outside of the semiconductor wafer processing device 100. Next, a control of controlling the temperature of the fluid L using the fluid temperature adjusting device 1 will be described.

Fluid Temperature Control

FIG. 3 is a control block diagram of the controller included in the fluid temperature adjusting device according to the embodiment. FIGS. 4 and 5 are diagrams illustrating a change in the upper limit value of the operation amount. FIG. 6 is a diagram illustrating an example of the operation amount of the peltier module and the operation amount of the heater.

When the fluid temperature adjusting device 1 illustrated in FIG. 1 adjusts the temperature of the fluid L to a temperature suitable of cleaning the semiconductor wafer W, the controller 11 receives an input of an operation amount MV illustrated in a control block B1. As the operation amount MV, it is possible to use, for example, an operation amount of a PID control using the control device 2 illustrated in FIG. 1, that is, an operation amount which is defined based on a difference between the target temperature of the fluid L suitable for cleaning the semiconductor wafer W and the temperature of the fluid L of which the temperature is adjusted by the cooling and heating device 20. Further, the operation amount MV may be an operation amount (an external operation amount input) which is input from the outside to the controller 11 through a communication line and the like.

When the seal portion of the cooling and heating device 20 is overheated, there is a concern that the durability of the seal portion may be degraded and the sealing performance may be degraded. For this reason, a limit value (a seal portion protection upper limit value) is defined from the temperature of the seal portion. The seal portion protection upper limit value is provided so as to protect the seal portion of the cooling and heating device 20 illustrated in FIGS. 1 and 2 from overheating. The seal portion of the cooling and heating device 20 is a portion which is necessary to realize the seal function, and is, for example, an O-ring, a backup ring, an adhesive, or a liquid contact member which is interposed between the heat transfer member 24 and the fluid passageway 21 illustrated in FIGS. 1 and 2. In general, since it is difficult to measure the temperature of the seal portion, the temperature may be estimated from the temperature of the heat transfer member 24.

In the embodiment, the controller 11 sets a seal portion protection upper limit value MVsl illustrated in FIG. 4 based on a heat transfer member temperature PV3. The controller 11 compares the set seal portion protection upper limit value MVsl with the output (operation amount) MV of the control block B1, and sets the small one as an output MVs. Accordingly, the output MVs of a control block B2 becomes a small one of the outputs MV and MVsl of the control block B1.

As illustrated in FIG. 4, the seal portion protection upper limit value MVsl changes from −1 to 1. Further, the seal portion protection upper limit value MVsl changes based on the temperature (heat transfer member temperature) PV3 of the heat transfer member 24. The heat transfer member temperature PV3 is measured by the heat transfer member temperature sensor 32 which is provided in the heat transfer member 24.

In the embodiment, the seal portion protection upper limit value MVsl is 1 until the heat transfer member temperature PV3 is a predetermined temperature T4. At this time, the output MVs of the control block B2 becomes MVs=MV. When the heat transfer member temperature PV3 becomes higher than the temperature T4, the seal portion protection upper limit value MVsl decreases with an increase in the heat transfer member temperature PV3. The output MVs of the control block B2 becomes a small one of MVsl and MV. In a region where the heat transfer member temperature PV3 is equal to or higher than T4, the output MVs of the control block B2 becomes smaller than the operation amount MV as a result in which the upper limit value is set in the operation amount MV.

In a region where the heat transfer member temperature PV3 is equal to or higher than T4, the seal portion protection upper limit value MVsl linearly and continuously decreases according to a linear function with an increase in the heat transfer member temperature PV3. In this example, when the heat transfer member temperature PV3 is equal to T5 (>T4), the seal portion protection upper limit value MVsl is 0. That is, since the output MVs of the control block B2 becomes 0, the operation amount MV of the heater 22 and the peltier module 23 becomes 0.

When the heat transfer member temperature PV3 becomes higher than T5, the seal portion protection upper limit value MVsl linearly and continuously decreases according to a linear function with an increase in the heat transfer member temperature PV3, and hence becomes a negative value. When the seal portion protection upper limit value MVsl becomes a negative value, the output MVs of the control block B2 becomes a negative value. This means that the cooling and heating device 20 is cooled. The controller 11 performs a control so that the peltier module 23 is cooled based on the output MVs. When the heat transfer member temperature PV3 becomes T6, the seal portion protection upper limit value MVsl becomes −1, that is, the negative maximum value. At this time, the peltier module 23 exhibits the maximum cooling capability. Further, when the temperature of the seal portion increases due to a disturbance or the like, the seal portion is promptly cooled by driving the peltier module 23 in the cooling direction, so that the seal portion may be protected.

As described above, the seal portion protection upper limit value is provided so as to protect the seal portion of the cooling and heating device 20. In order to protect the seal portion, it is desirable to directly measure the temperature of the seal portion. However, since it is difficult to attach the thermometer, it is difficult to directly measure the temperature of the seal portion. For this reason, in the embodiment, the seal portion protection upper limit value is set based on the heat transfer member temperature PV3 which is highly involved with the temperature of the seal portion.

In this way, since it is possible to more accurately detect the temperature of the seal portion by using the heat transfer member temperature PV3 which is highly involved with the temperature of the seal portion, it is possible to more reliably protect the seal portion. Further, since it is possible to more reliably detect the temperature of the seal portion, it is possible to maximally exhibit the capability of the cooling and heating device 20 by increasing the seal portion protection upper limit value when there is an allowance in the temperature of the seal portion. Further, the heat may not be easily transferred depending on the type of the fluid L (for example, sulfate or ethylene glycol). When heating the fluid L to which the heat is not easily transmitted, the heat transfer member temperature PV3 may high even when the outlet temperature PV1 is low. In the embodiment, since the seal portion protection upper limit value based on the heat transfer member temperature PV3 is used in addition to the module protection upper limit value based on the outlet temperature PV1, it is possible to more reliably protect the seal portion even when heating the fluid L to which the heat is not easily transmitted. That is, in the embodiment, it is possible to reliably protect the seal portion even when heating a plurality of types of fluids L having different heat transfer degrees.

When the output MVs in which the seal portion protection upper limit value is set in the operation amount MV may be obtained, in the control block B3, the controller 11 sets an upper limit value (module protection upper limit value) MVjl of the thermal energy supplied to the fluid L based on the temperature (the outlet temperature) PV1 of the fluid L which is adjusted by the heat transfer member 24 of the cooling and heating device 20 illustrated in FIGS. 1 and 2.

The junction temperature of the peltier module 23 may be overheated even when adopting the seal portion protection upper limit value depending on the temperature or the flow rate of the fluid L. For this reason, in the embodiment, the module protection upper limit value (the limit value) is defined by measuring the temperature of the junction. The junction indicates the bonding portion between the peltier element and the electrode. The controller 11 which receives the input of the operation amount MV sets the upper limit value (the module protection upper limit value) MVjl of the thermal energy supplied to the fluid L so as to protect the junction of the peltier module 23 illustrated in FIGS. 1 and 2 in the control block B3. In the embodiment, the controller 11 sets the module protection upper limit value MVjl based on the relation between the temperature (the outlet temperature) PV1 of the fluid L and the module protection upper limit value MVjl illustrated in FIG. 5. Then, the controller 11 compares the set module protection upper limit value MVjl with the output MVs of the control block B2 and sets the small one as the output MVj. Accordingly, the output MVj of the control block B3 becomes the small one between the module protection upper limit value MVjl and the output MVs of the control block B2.

As illustrated in FIG. 5, the module protection upper limit value MVjl changes from 0 to 1. Further, the module protection upper limit value MVjl changes based on the temperature (the outlet temperature) PV1 of the fluid L of which the temperature is adjusted by the cooling and heating device 20. Accordingly, the module protection upper limit value also changes based on the outlet temperature PV1 (after the heating in the heating) after the adjustment of the temperature by the cooling and heating device 20. The outlet temperature PV1 is measured by the outlet temperature sensor 31 which is provided at the downstream side of the fluid outlet 21E of the cooling and heating device 20. The reason why the outlet temperature PV1 is used is generally because it is difficult to directly measure the temperature of the junction. Accordingly, the temperature of the junction is estimated from the outlet temperature PV1.

In the embodiment, the module protection upper limit value MVjl is 1 until the outlet temperature PV1 is a predetermined temperature T1. At this time, the output MVj of the control block B3 becomes MVj=MVs. Until the outlet temperature PV1 becomes higher than the temperature T1 and becomes the temperature T2, the outlet temperature PV1 increases and the module protection upper limit value MVjl decreases. As the output MVj of the control block B3, a small one is selected from the operation amount MVs and the module protection upper limit value MVjl in a region where the outlet temperature PV1 is equal to or higher than T1.

In a region where the outlet temperature PV1 is equal to or higher than T1, the module protection upper limit value MVjl linearly and continuously decreases according to a linear function with an increase in the outlet temperature PV1. In this example, the module protection upper limit value MVjl is 0.15 when the outlet temperature PV1=T2 (>T1). When the outlet temperature PV1 becomes higher than T2, the module protection upper limit value MVjl rapidly decreases compared to the case where the outlet temperature PV1 does not become higher than T2, and becomes 0 when the outlet temperature PV1=T3 (>T3). Here, the limitation value (the module protection upper limit value MVjl) linearly decreases, but since the limitation value is provided for the purpose of limiting the junction temperature at a predetermined temperature or less, the limitation value may partially increase or decrease the module protection upper limit value MVjl according to the allowance degree of the junction temperature (the same applies to the following description).

The junction temperature is set to a predetermined temperature or less so as to protect the peltier module 23. In order to protect the junction, it is desirable to directly measure the temperature of the junction. However, it is difficult to directly measure the temperature of the junction due to the difficulty in the attachment of the thermometer and the influence of the heater 22. Here, the junction is largely influenced by the heater 22, but the limitation value (the module protection upper limit value) for protecting the peltier module 23 is defined from the outlet temperature PV1 which is involved with the junction temperature to some extent. Since a constant relation is established between the operation amount of the peltier module 23 and the operation amount of the heater 22, the limitation value, that is, the module protection upper limit value of the operation amount of the peltier module 23 in consideration of the influence of the temperature of the heater 22 may be defined.

In this way, since it is possible to more accurately detect the temperature of the junction by using the outlet temperature PV1 which is highly involved with the temperature of the junction, it is possible to more reliably protect the junction. Further, since it is possible to more accurately detect the temperature of the junction, when there is an allowance in the temperature of the junction, the module protection upper limit value is increased so as to exhibit the capability of the peltier module 23 as much as possible.

When the heat generation amount of the peltier module 23 increases due to the use for the heating, the temperature of the junction also increases. In the embodiment, the module protection upper limit value MVjl decreases with an increase in the outlet temperature PV1. That is, the output MVj of the control block B3 decreases with an increase in the outlet temperature PV1. Since the outlet temperature PV1 increases with an increase in the heat generation amount of the peltier module 23, it is possible to more reliably protect the junction by decreasing the module protection upper limit value with an increase in the outlet temperature PV1 as described above.

In this way, in the embodiment, the smallest value of the operation amount MV, the seal portion protection upper limit value MVsl, and the module protection upper limit value MVjl is set as the operation amount MVj of the heater 22 and the peltier module 23. In the above-described example, the seal portion protection upper limit value MVsl and the module protection upper limit value MVjl are set in this order, but the order of obtaining these values may be reversed.

In the embodiment, the controller 11 feed-backs the output of the control block B3, that is, the operation amount MVj to the PID control using the control device 2 in the control block B1. In this way, since the operation amount MVj with the set upper limit value is fed-back to the PID control, the unnecessary integration in the PID control is stopped, thereby suppressing the overshoot or the undershoot.

When the process of setting the upper limit value in the operation amount MV (the processes of the control blocks B2 and B3) ends, in the control block B4, the controller 11 divides the operation amount MV with the set upper limit value in the control block B2 and the control block B3, that is, the operation amount MVj (hereinafter, referred to as MVc) as the output of the control block B3 into an operation amount (heater operation amount) MVh of the heater 22 and an operation amount (module operation amount) MVm of the peltier module 23 (the division of the operation amount). The operation amount MVj as the output of the control block B3 corresponds to the thermal energy for heating the fluid L. Since the operation amount is divided, particularly when heating the fluid L so as to be kept at the target temperature, the thermal energy may be given from both the heater 22 and the peltier module 23 to the fluid L. As a result, it is possible to shorten a time until the temperature of the fluid L becomes the target temperature by effectively using both heating capabilities.

In the division of the operation amount, a module operation amount dividing coefficient MVmk illustrated in FIG. 6 is used. Before dividing the operation amount, the maximum and minimum operation amounts of the fluid temperature adjusting device 1 are expressed by ±1. Further, after dividing the operation amount, the maximum and minimum operation amounts of the peltier module 23 are expressed by ±1. The maximum operation amount of the heater is expressed by +1. The module operation amount dividing coefficient MVmk is a coefficient which corresponds to the module operation amount MVm (corresponding to the supply amount of the peltier module 23 in the thermal energy for heating the fluid L) in the output MVc. The module operation amount dividing coefficient MVmk is equal to or larger than 0 and equal to or smaller than 1.

When the range of the output MVc is from 0 to 1, the ranges of the module operation amount MVm and the heater operation amount MVh are also from 0 to 1. When the module operation amount dividing coefficient MVmk is used, the module operation amount MVm becomes 2×MVc×MVmk (here, 0≦MVm≦1). Further, in the output MVc, the heater operation amount MVh (corresponding to the supply amount of the heater 22 in the thermal energy for heating the fluid L) becomes 2×MVc×(1−MVmk) (here, 0≦MVc≦1).

Here, the module operation amount dividing coefficient MVmk is equal to or larger than 1-1/(2×MVc) and equal to or smaller than 1/(2×MVc) and is equal to or larger than 0 and equal to or smaller than 1. The dashed line illustrated in FIG. 6 indicates the upper and lower limits of the module operation amount dividing coefficient MVmk. Furthermore, the range of the above-described module operation amount dividing coefficient MVmk corresponds to the case where the rated heating output of the peltier module 23 and the rated heating output of the heater 22 are equal to each other. When both outputs are different from each other, there is a need to consider the ratio between the respective heating capabilities.

When the module operation amount dividing coefficient MVmk is set to the range from 1-1/(2×MVc) to 1/(2×MVc) and from 0 to 1, the module operation amount MVm and the heater operation amount MVh may be set to the range from 0 to 1. When the module operation amount dividing coefficient MVmk becomes constant with respect to a change in the output MVc, the ratio between the module operation amount MVm and the heater operation amount MVh is also constant with respect to a change in the output MVc. That is, in the thermal energy for heating the fluid L, the ratio between the supply amount of the heater 22 and the supply amount of the peltier module 23 does not change by the magnitude of the thermal energy supplied to the fluid L.

In the embodiment, the controller 11 changes the ratio between the supply amount of the heater 22 and the supply amount of the peltier module 23 in the total thermal energy for heating the fluid L based on the magnitude of the thermal energy supplied to the fluid L. For this reason, the ratio between the module operation amount MVm and the heater operation amount MVh is changed with respect to a change in the output MVc by changing the module operation amount dividing coefficient MVmk with respect to a change in the output MVc. As a result, the ratio between the supply amount of the heater 22 and the supply amount of the peltier module 23 of the thermal energy for heating the fluid L changes with a change in the magnitude of the thermal energy supplied to the fluid L. The above-described ratio is a ratio between the heater 22 and the peltier module 23 with respect to the thermal energy supplied to heat the fluid L.

In the embodiment, the module operation amount MVm and the heater operation amount MVh are divided by setting the module operation amount dividing coefficient MVmk in consideration of the following points (1) to (5).

(1) While the output MVc changes from 0 to 1, the module operation amount MVm and the heater operation amount MVh are also monotonously increased in the above-described range so that a monotonous increase in the total thermal energy given to the fluid L is kept. In a region where the total thermal energy given to the fluid L decreases, the total thermal energy given to the fluid L may decrease regardless of an increase in the output MVc (the operation amount). As a result, there is a concern that hunting in the temperature of the fluid L may occur. With the above-described configuration, it is possible to reduce a concern that hunting in the temperature of the fluid L may occur by monotonously increasing the total thermal energy given to the fluid L.

(2) The module operation amount MVm is smoothly changed. With such a configuration, it is possible to prevent an excessive change in the temperature of the junction of the peltier module 23. As a result, when a change in the output MVc (the operation amount) is small, an abrupt change in the temperature of the peltier module 23, and particularly, the temperature of the junction may be suppressed, and hence degradation in the durability of the peltier module 23 may be suppressed.

(3) When the total thermal energy given to the fluid L is smaller than a predetermined value, in the total thermal energy for heating the fluid L, the supply amount of the peltier module 23 is made to be larger than the supply amount of the heater 22. Specifically, in a region where the output MVc (the operation amount) is smaller than a predetermined value (for example, a region where the output MVc is smaller than 0.5 to 0.6), the module operation amount MVm is made to be larger than the heater operation amount MVh.

When the peltier module 23 is used for heating, the heating efficiency becomes higher than that of the heater 22 due to the peltier effect. For this reason, when the module operation amount MVm is made to be larger than the heater operation amount MVh, the heating efficiency of the fluid L is improved. As a result, the power consumption may be suppressed. Particularly, in a region where the output MVc (the operation amount) is small, a difference in the heating efficiency increases. Accordingly, in such a region, it is desirable to heat the fluid L only by the peltier module 23.

Furthermore, when a switching power supply is used as the power supply of the peltier module 23, the efficiency is degraded in a region where the load with respect to the power supply is small. For this reason, the efficiency of the switching power supply is degraded in a region where the output MVc (the operation amount) is extremely small (for example, the module operation amount MVm is 0.2 or less). In the embodiment, the fluid L is heated only by the peltier module 23 in a region where the output MVc (the operation amount) is extremely small. With such a configuration, since the amount of heating the fluid L by the heater 22 is obtained from the peltier module 23, the load of the switching power supply increases by the amount, the region where the efficiency of the switching power supply is low may not be used as much as possible. In the embodiment, for example, when the output MVc (the operation amount) is 0.1 or less (the module operation amount MVm corresponds to 0.2 or less), the use of the region where the efficiency of the switching power supply is low may be suppressed only by the heating of the peltier module 23.

Further, since the module operation amount MVm is made to be larger than the heater operation amount MVh, the control when heating the fluid L may be improved. For example, when the heater 22 is controlled by a power control method such as a cycle control in which the output changes step-wisely, the output resolution of the peltier module 23 is smaller than that of the heater 22, and it is possible to effectively suppress degradation in the control precision of the temperature of the fluid L due to the heating of the heater 22 having a low output resolution.

(4) When the total thermal energy given to the fluid L becomes a predetermined value or more, in the total thermal energy for heating the fluid L, the supply amount of the heater 22 is made to be larger than the supply amount of the peltier module 23. Specifically, in a region where the output MVc (the operation amount) is a predetermined value or more (for example, a region where the output MVc is 0.5 to 0.6 or more), the heater operation amount MVh is made to be larger than the module operation amount MVm. As a result, according to an increase in the total thermal energy supplied to the fluid L, a state where the thermal energy supplied from the peltier module 23 to the fluid L is larger than the thermal energy supplied from the heater 22 to the fluid L changes to a state where the thermal energy supplied from the heater 22 to the fluid L is larger than the thermal energy supplied from the peltier module 23 to the fluid L. That is, the maximum heating capability of the heater 22 becomes larger than the maximum heating capability of the peltier module 23 with an increase in the total thermal energy supplied to the fluid L. In this way, in the embodiment, the small and large degrees of the thermal energy supplied from the heater 22 to the fluid L and the thermal energy supplied from the peltier module 23 to the fluid L are switched. That is, the small and large degrees of the operation amount of the heater 22 and the operation amount of the peltier module 23 are switched.

With such a configuration, in a region where the output MVc (the operation amount) is a predetermined value or more, the load on the peltier module 23 may be reduced by further sharing the energy using the heater 22 in the total thermal energy supplied to the fluid L. As a result, it is possible to effectively suppress degradation in the durability of the peltier module 23, and more specifically, the junction by suppressing an increase in the temperature of the junction of the peltier module 23.

(5) The module operation amount dividing coefficient MVmk is continuously changed. With such a configuration, the module operation amount MVm and the heater operation amount MVh may be continuously changed. Then, even when the module operation amount MVm and the heater operation amount MVh change, the thermal energy supplied from the peltier module 23 to the fluid L and the thermal energy supplied from the heater 22 to the fluid L smoothly change. As a result, since an abrupt change in the temperature of the fluid L is suppressed even when the module operation amount MVm and the heater operation amount MVh are changed, it is possible to decrease an influence on the quality of the semiconductor wafer W which is cleaned by the fluid L.

FIG. 6 illustrates an example in which the module operation amount dividing coefficient MVmk is set according to (1) to (4). For example, in a region where the output MVc (the operation amount) is about 0.1, the module operation amount MVm is larger than 0, and the heater operation amount MVh becomes 0. For this reason, the fluid L is heated only by the peltier module 23. In a region where the output MVc (the operation amount) is from about 0.1 to 0.8, the module operation amount dividing coefficient MVmk monotonously decreases. In this region, the module operation amount MVm and the heater operation amount MVh both become larger than 0. For this reason, the fluid L is heated by both the heater 22 and the peltier module 23.

When the output MVc (the operation amount) is about 0.53, the module operation amount dividing coefficient MVmk becomes 0.5. At this time, the module operation amount MVm and the heater operation amount MVh both become 0.5. For this reason, the fluid L is heated by both the heater 22 and the peltier module 23, and the thermal energies given to the fluid L therefrom become equal to each other.

When the output MVc (the operation amount) becomes larger than about 0.8, the module operation amount dividing coefficient MVmk monotonously increases and becomes 0.5 when the output MVc (the operation amount) is 1. In this region, the module operation amount MVm and the heater operation amount MVh monotonously increase, but the increase rate of the heater operation amount MVh becomes smaller in a region where MVmk is smaller than 0.8. At MVc=1, the heater 22 and the peltier module 23 both give the thermal energy to the fluid L at the maximum output so as to heat the fluid L when the module operation amount dividing coefficient MVmk=0.5.

Furthermore, when the thermal energy supplied to the fluid L changes, the controller 11 may change the respectively supplied thermal energies while keeping the ratio between the ratio (the operation amount) of the heating output with respect to the maximum heating capability of the peltier module 23 and the ratio (the operation amount) of the heating output with respect to the maximum heating capability of the heater 22. With such a configuration, a relation of MVm=MVh=MVc is established as illustrated in FIG. 6.

In this way, when the module operation amount dividing coefficient MVmk is set, the controller 11 may switch the operation amount of the peltier module 23 and the operation amount of the heater 22, and may control the cooling and heating device 20 so that a state where the thermal energy supplied from the peltier module 23 to the fluid L is larger than the thermal energy supplied from the heater 22 to the fluid L becomes a state where the thermal energy supplied from the heater 22 to the fluid L is larger than the thermal energy supplied from the peltier module 23 to the fluid L with an increase in the total thermal energy supplied to the fluid L. As a result, it is possible to effectively obtain an effect that the control is improved and an increase in the temperature of the junction of the peltier module 23 is suppressed. Further, since the controller 11 adjusts the temperature of the fluid L to the target temperature when the operation amount in the control block B1 is defined, the operation may be easily performed. As a result, the fluid temperature adjusting device 1 does not easily cause a problem due to an erroneous operation, and there is an extremely low possibility that the cleaning failure of the semiconductor wafer W may occur. The description above corresponds to a case where the heating capabilities of the peltier module 23 and the heater 22 are equal to each other. When the heating capabilities of the peltier module 23 and the heater 22 are different from each other, the ratio between each supply heating capability with respect to each maximum heating capability may be used.

The controller 11 sets the module operation amount MVm and the heater operation amount MVh by dividing the output MVc into the operation amounts based on the module operation amount dividing coefficient MVmk. Subsequently, the controller 11 performs a cycle control or a duty control of the power supplied to the heater 22 based on the heater operation amount MVh. It is possible to easily control the heating amount of the heater 22 by performing a cycle control or a duty control on the power supplied to the heater 22.

The cycle control is a method of controlling the power supplied to the heater 22 by turning on or off an AC power supply by the unit of a half wave or a cycle of the AC power supply. The duty control is a method of controlling the power supplied to the heater 22 by changing the time in which the AC power supply is turned on for a predetermined time (for example, one second). Since the cycle control or the duty control may control the power supplied to the heater 22 with high precision compared to the simple ON and OFF control, the heating amount of the heater 22 may be controlled with high precision.

According to the invention, it is possible to shorten a time until a temperature of a fluid becomes a target temperature in a fluid temperature adjusting device including a peltier module and a heater.

Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth. 

What is claimed is:
 1. A fluid temperature adjusting device comprising: a heater configured to heat a fluid passing through a fluid passageway; a peltier module including a plurality of peltier elements, the peltier module being configured to heat or cool the fluid passing through the fluid passageway; and a controller configured to divide a total thermal energy for keeping the fluid at a target temperature into a thermal energy to be supplied from the heater and a thermal energy to be supplied from the peltier module to give the total thermal energy from both the heater and the peltier module to the fluid.
 2. The fluid temperature adjusting device according to claim 1, wherein the controller is configured to change a ratio between an operation amount of the heater and an operation amount of the peltier module depending on a magnitude of the thermal energy to be supplied to the fluid.
 3. The fluid temperature adjusting device according to claim 2, wherein the controller is configured to control the heater and the peltier module so that the operation amount of the peltier module becomes larger than the operation amount of the heater when the total thermal energy to be supplied to the fluid is smaller than a predetermined value.
 4. The fluid temperature adjusting device according to claim 1, wherein the controller is configured to supply power to the heater by a cycle control or a duty control.
 5. The fluid temperature adjusting device according to claim 1, wherein the controller is configured to change the thermal energy to be supplied by each of the peltier module and the heater while keeping a ratio between an operation amount of the peltier module and an operation amount of the heater at a constant value when the thermal energy to be supplied to the fluid changes.
 6. The fluid temperature adjusting device according to claim 1, wherein the controller is configured to monotonously increase a supply amount of the heater and a supply amount of the peltier module. 